Diamonds are created from one of the most abundant substances on earth – carbon. A pure natural raw diamond is 100% carbon, placed under intense pressure for millions of years. But how does that natural process happen, and how do we end up with rough diamonds on the surface of the earth?
HOW DIAMONDS ARE FORMED
Of course, today, rough diamonds can be formed in laboratories. The method that the laboratories use mimics the natural process that diamonds undergo within the earth. Lab created raw diamonds are not natural diamonds, and are distinct from natural rough diamonds in a few ways that we’ll explain in a later article.
Carbon is one of the simplest elements and major building blocks of our earth. It is estimated that the earth contains 1.85 billion tons of carbon. And, 99% of that carbon is beneath the surface of the earth.
Scientists debate where all this carbon came from originally. One of the most spectacular – and commonly accepted - hypotheses is that it came from a collision with another planet around 4.4 billion years ago. Which means that diamonds are really dust and gas from extraterrestrial planets and stars!
Carbon appears itself in the form of gas under the upper mantle of the earth. The mantle sits just below the continental plates, between 90 – 125 miles under the surface of the earth. The temperature and pressure in that space is so intense that the carbon is compressed. This compression over many millions of years is the process that creates diamonds. It’s estimated that most of the natural rough diamonds we have today on the surface of the earth are about 300 million years old.
HOW ROUGH DIAMONDS TRAVEL TO THE SURFACE OF THE EARTH
At this point in history, we have no way to drill down to beneath the mantle. Diamonds have to make their way to the surface on their own. Fortunately, nature has its own ways of doing this.
First, volcanoes originate from violent explosions that occur beneath the mantle. The explosions are so strong that they create a giant hole in the rock above where the lava spews from beneath to the earth’s surface. These holes are called kimberlite pipes. When the volcano explodes, not only does lava come to the surface, but also diamonds.
The diamonds that reach the surface during a volcanic explosion dissipate into the atmosphere. However, the kimberlite pipes remain open for millions of years, and diamonds can be found in their depths. Many modern large-scale mines are located within the kimberlite pipes of ancient volcanoes since the pipes give humans access to the depths of the earth.
Also, riverbeds or bodies of water flow over kimberlite pipes. The natural sedimentary process that occurs over millions of years causes the water flow to carry diamonds from the kimberlite pipes to other areas on the surface, in riverbeds, or even in the oceans. These types of diamonds are called alluvial diamonds, and they are often smoothed by their many thousands or millions of years by water streaming over their surface.
THE COAL QUESTION – ARE DIAMONDS CREATED FROM COAL?
This is one of the most common misconceptions about rough diamonds. Though it is a beautiful metaphor, diamonds are not created from coal. Coal is built from the results of decay and sediment of dead plants and animals over thousands of years. Diamonds originate from a time before any plants or animals appeared on the surface of the earth. Therefore, there is no way that diamonds could have been created from coal. While the two are made from the same building block – carbon – diamonds and coal are completely different.